Comfort HC-600 IR panels - what thermostat (if any) do I need?

I'm looking to buy two Comfort HC-600 I panels to be ceiling mounted in a new extension room.

Do I need to buy a separate thermostat? If so, what model, and does it need to be mains wired in as well? Can I control both units off the one thermostat

Is a simple unthermostatted on/off operation also possible?

Cheers

John